Most people are reluctant to acknowledge their own vulnerability to harm. Their optimistic biases can inhibit precautions, increasing the risk of injury, illness, and emotional trauma. Exposure to disasters, however, can temporarily eliminate these biases, even among people who are not directly affected. The investigation will examine the impacts of three tornadoes on people who live in communities that have suffered major losses, but who have not suffered any injury or damage themselves. Through telephone interviews, it will examine their initial reactions and their reactions at a later point in time when optimistic biases have returned. Control communities will also be examined. The first goal of the study concerns the loss of optimistic biases. The aim is to understand how disaster exposure in the absence of victimization overcomes optimistic biases about personal risk. Specific hypotheses concerning the mechanisms and processes that mediate these effects will be tested, including such possibilities as loss of perceived behavioral control, loss of perceived cognitive control, increased attentional focus, increased vividness, increase in negative affect, and interference with daily living. The second major focus is on the recovery of optimistic biases. What changes in beliefs about the hazard, changes in cognitive activity, or changes in affect take place among those who recover most quickly? Corresponding to each of these two major goals is a potential application. First, the findings may help us to understand how to encourage realistic risk perceptions in situations where unrealistic optimism increases the likelihood of victimization. Second, by showing how people recover from indirect, disaster-exposure effects, the study may help us understand what issues to focus on when assisting people who suffer more serious trauma.